Abstract: We present total cross sections for single and double ionization of helium byantiproton impact over a wide range of impact energies from 10 keV-amu to 1MeV-amu. A non-perturbative time-dependent close-coupling method TDCC isapplied to fully treat the correlated dynamics of the ionized electrons.Excellent agreement is obtained between our calculations and experimentalmeasurements of total single and double ionization cross sections at highimpact energies, whereas for lower impact energies, some discrepancies withexperiment are found. At an impact energy of 1 MeV we also find that thedouble-to-single ionization ratio is twice as large for antiproton impact asfor proton impact, confirming a long-standing unexpected experimentalmeasurement.